In cases where a cable for a telephone or LAN is connected, a modular plug such as RJ11 (for telephone use) and RJ45 (for LAN use) is generally employed. Such a modular plug is designed to be connected to a modular jack installed in a LAN port, patch panel, rosette, or the like of a network device such as a telephone or HUB.
For example, the modular plug and modular jack described in JP-A-2002-305061 are known as a conventional modular plug and modular jack. As is shown in FIGS. 11 and 12, the modular plug 101 is connected to the front end portion (left end portion in FIG. 11) of a plug cable 113 such as a LAN cable, and comprises a substantially rectangular plug main body 110 and a plurality of plug contacts 120 attached in a single row to the plug main body 110. Furthermore, a plurality of guide grooves 111 that are formed so that the respective plug contacts 120 are exposed are formed in the undersurface of the plug main body 110. Moreover, a cantilevered lock arm 112 that extends rearward at an inclination toward the top from the front-end corner portion of the plug main body 110 is formed so as to protrude from the upper surface of the plug main body 110. In addition, the plug conductors 114 of the plug cable 113 are connected to the respective plug contacts 120.
Furthermore, as is shown in FIGS. 13 and 14, the modular jack 201 comprises a substantially rectangular jack housing 210 that has on the inside a jack recess 211 for mating with the modular plug 101, and a plurality of jack contacts 220 attached in a single row to the jack housing 210. The respective jack contacts 220 are disposed so as to extend rearward at an inclination toward the top from the front end (right end in FIG. 13) of the bottom portion of the jack recess 211, and the rear end portions of the jack contacts 220 are connected to the jack conductors 231 of a jack cable 230.
Moreover, as is shown in FIG. 15, when the modular plug 101 is inserted into the jack recess 211 of the modular jack 201, the lock arm 112 of the modular plug 101 is locked with a locking part 212 provided on the jack recess 211, so that the modular plug 101 and modular jack 201 are locked together. In this case, the jack contacts 220 provided on the modular jack 201 are guided by the guide grooves 111 of the modular plug 101, and make contact with the plug contacts 120 of the modular plug 101, so that the plug cable 113 and jack cable 230 are electrically connected to each other, allowing the mutual exchange of data. In addition, when the mating between the modular plug 101 and modular jack 201 is to be released, the locked state of the lock arm 112 with the locking part 212 may be released by pushing the portion of the lock arm 112 of the modular plug 101 that protrudes from the jack housing 210 of the modular jack 201 downward with a finger, so that the modular plug 101 can simply be pulled out of the jack recess 211 of the modular jack 201.
However, the following problems have been encountered in the conventional modular plug 101 shown in FIGS. 11 and 12.
Specifically, when the mating between the modular plug 101 and modular jack 201 is to be released, there are cases in which the operation of the lock arm 112 by the finger is difficult. Due to a trend toward high-density mounting of the modular jack 201, in particular, there are cases in which the finger cannot reach the lock arm 112 because of the presence of the plug cable 113 attached to the modular plug 101 that mates with the modular jack 201, and in such cases, the operation of the lock arm 112 by the finger is impossible.